Outside of theatre, Thomas also writes for the concert platform. In 2000 he won a Year of the Artist award to compose a song cycle, Songs You Can Sing on a Small Train, with librettist Karen Hayes, a long-time collaborator, developed from a series of interviews conducted on the Gloucester to Bristol train. Soon after that, he was commissioned to write his first oratorio, Gilgamesh, for Stroud Community Choir, for full choir and a chamber ensemble (libretto by Farhana Sheikh). More recently with Karen once again as librettist, he won a commission from the Heritage Lottery Fund to compose a second oratorio, Street of Bugles, for Gloucestershire Youth Orchestra and Choir. Premiered in Cheltenham Town Hall, this piece went on to help GYO win a place at the Music for Youth finals, performing the piece at Birmingham Symphony Hall where it won the Music for Youth Award for Innovation. In 2016 Street of Bugles was performed again in Gloucester Cathedral as part of the Three Choirs Festival. As an 'encore' to the oratorio, Thomas was commissioned by the Three Choirs Festival to write Four Songs for the End of Wars, composed specially for the Gloucester Cathedral bells and Cheltenham Youth Choir, performed on the cathedral green. This was the first time a new piece was written for the cathedral bells in 400 years.  In 2022 Fire Songs was premiered, an hour-long choral song cycle and multi-sensory theatre piece for audiences living with Profound and Multiple Learning Disabilities. Music and lyrics by Thomas, produced by Frozen Light.